Method of separating and purifying fullers&#39; earth and analogous materials.



c. c. RUPREOHT. METHOD OF SEPARATING AND PUR IFYING FULLERS EARTH AND ANALOGOUS MATERIALS.

APPLICATION FILED AUG. 5, 1910.

Patented Apr. 23, 1912.

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CHARLES C. RUIREGE'I, F IBLAKELY, ALABAMA.

METHOD OF SEPARATING- AND PURIFYING FULLERS EARTH AND ANALOGOUS MATERIALS.

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Specification of Letters Patent.

Patented Apr. 23,1t9i2.

To all whom it may concern:

Be it known that I CHARLES C. RUPRECHT,

a citizenof the United States,residing at Blakely, in the county of Baldwin and State of Alabama, have invented a certain new and useful Improvement in Methods of Separating and Purifying Fullers Earth and Analogous Materials, of which the following is a full, clear, and exact description, re erence being had to the accompanying drawings.

This invention relates to a method for separating fullers earth and other materials of like character from a fluid medium and for improving the bleaching and other desirable qualitles of such materials.

In many de osits of fullers earth there is an excess 0 deleterious material, either in the form of organic matter or of minerals, both of which are undesirable because of their obstructive nature their tendency to decay or because of their abrasive efiect. To secure the earth in its best condition and freed from such materials, it is found necessary to wash the earth by mixing it thoroughly with water and allowing the slip or mixture of earth and water to pass rather slowly through long tanks or settling vats in which the excess of sand and other deleterious minerals will be quite-completely deposited. It is found, however, that when this settling has been carried to a certain extent the earth itself will settle with extreme slowness from the water and remains in suspension for weeks or months. Consequently, the mixture of earth and water remainin after the ordinary Washing is very fiui and the importance of securing the slip in the most dense condition possible to. insure rapid recovery, renders it necessary to extract this excess water which, under ordinary conditions, is a very expensive process. Furthermore, the specific gravity of some of the organic contaminations is such that they will not settle out thoroughly, and, under ordinary treatment, the earth is not obtained in a condition suitable for all purposes, such, for instance, as the purification of edible oils.

The object of this invention is a process for rapidly and economically precipltating thissuspended earth and simultaneously decomposmg and removing the organic conelectrolyzed, the earth is immediatel precipltated and the deposit so obtaine is so hard that what little remaining water is occluded in its pores may be easily removed by a simple expedient, as by the use of filter presses, centrifugal driers, or evaporation in suitable kilns. At the same time, the orgame matter is broken up, either by the direct actlon'of the electric current, or by a secondary chemical reaction with the substances produced by the electrolysis.

In the drawin s accompanying and forming a part hereo an apparatus is illustrated by which my process may be realized.

In these drawings Figure 1 illustrates a sectional elevation of the complete apparatus; Fig. 2 a top view of the electrical treating vat; and Fig. 3 a top view of the settling vat.

Referring more particularly to the drawings by reference characters, A denotes a mixing and scrubbing mill into which raw fullers earth is fed at a fairly constant rate from a hopper or platform 1 and thoroughly mixed with water, supplied through a pipe 2, by means of revolving paddles 3 or other similar well known means. From this mill the slip is conducted by a pipe 4: into a suitable series of sand removing vats B, C and D, preferably arranged in cascade. I have found a convenient dimension of vat to be thirty feet by three feet by three feet, though this is not important; and more or less than three vats may be used, depending upon the amount of sand present. In some cases the vats may be entirely dispensed with. From the last of these vats the sandfree slip is delivered to an electrical treating vat E, as by a conduit 5. This vat consists of an oblong tank 6 having vertical electrodes 7, 7, arranged along the walls thereof as shown in F1 2. A convenient sizeof tank is 16 feet% 3 feet by 3 feet and, in the present em odiment, I have shown three anode plates of carbon each of which is preferably 16 inches square, and three copper cathodes each 3 feet wide by 4 feet long spaced 2 feet from the anodes, and arranged so that the slip may flow between them. The rate of flow in this vat is fairly rapid to prevent any great precipitation,

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and-I have found a current of about 150' amperes at 100 to volts to give excellent results. Inasmuch as the conductivity of the usual slip is very small, I find it nec' is used, the effect of the electric current is to evolve free chlorin and form sodium hypochlorite which act upon the earth to give it.

an added bleaching power and also destroy the organic material. This added bleaching power is apparently due partly to a certain amount of chlorin which is occluded in the pores of the earth and which is retained for an appreciable time, and partlyi to the fact that when dried the earth is in a' more porous condition than would otherwise have been the case. When sulfuric acid is used, the effect of the nascent hydrogen and a certain amount of ozone, which are evolved, is to destroy the organic matprefter in the same manner. The acid is erably used in cases where the earth 1s to be employed for the treatment of certain oils, such as linseed. In general, it may be: said that a current density of one-fifth ampere per square inch of positive electrode willl be very satisfactory, either for salts or SI I The use of carbon and copper electrodes is not'essential, since other conductors will op-' crate, but will require more frequent renewal. I employ a carbon anode, since car-1 bon isnot seriously acted upon by either chlorin or sulfuric trioxid. Copper forms a desirable cathode because of its high conductivity and is not injuriously affected by the chemical reactions in the vlcmity of the cathode.

From the vat E the slip is rapidly drawn: OK to a larger settling vat F by means of a conduit 8. The vat which I employ consists of a tank 9, 80 feet long by feet wideby 5 feet deep. These'dimensions are not, of course, compulsory, but the size of the tank should be sufficiently large to cause the to be com aratively.

movement of the sli slow. From the fart or end of t is tank a conduit 10 removes the clear water from the upper part of'the tank, until the tank is nearly full of almost solid earth. This de posit is periodically removed and dried in any convenient manner at a low temperature (not exceeding 400 F ah.), ground in any of the usual ways, and bolted to the desired mesh.

Electrodes may also be used in the large settling vat, where they have the effect of causing the earth to deposit rapidly and in moredense condition. Where used, I preferably arrange them in rows along the sides,

as shown in Fig. 3, the carbon anodes 11' alternating with the copper cathodes 12, electrodes of the same kind being connected in parallel. The number of plates or electrodes isimmateriaL-though'I. find a total anode surface of 100square feet employed in connection with a total .cathode surface of 150. square feet, with current at 'a'potentia'l of 100 to 1l0volts gives good results. Suflicient chemicals will ordinarily be retained in the liquid from the previous treatment to impart the necessary conductivity.

While I have described the above process especially in connection with the separation and refining offullers earth, I am aware.

that it may profitably be employed in refining and bleaching other materials, such for instance as kaolin, or for precipitating finely divided graphite, talc, gypsum, or the like,

from suspension in anorganic solution.

Having thus described my invent-ion,"what Iclaim is:

1. The process for separating fullers earth from organic impurities consisting in mixing the earth with water, rendering the water electrically conductive, and then submitting the water to electrolytic action, whereby the organieimpurities are destroyed and the earth precipitated.

2. A process for purifying and separating fullers earth consistlng in ,mixingthe earth with water, decanting the mixture from sand and like impurities in suitable tanks, addingchemicals to render the liquid conductive,- and electrolyzing the solution so formal.

3. An apparatus for separating and purifying fullers earth comprising a device for mixing the earth with water, means for removing the sand by gravity, and means for electro yzing the m xture ofearth and water.

4. An apparatus for separating and purifying fullers earth comprising'a device for mixing earth with water, means for removing the sand by gravity, means for electrolyzing the mixture of earth and water, and means for decanting 'thefiiiater from the deposited earth.

5. A. process. for recovering fullers. earth from'its suspension in water c'onsistingln causing the earth and water to assrapidly through an electrolytic. cell, an afterward decanting the water and drying'the deposited earth. v p j 6. The process of separating and purifying fullers earth consisting in mixing the earth with water, impregnatingthe mixture of earth and-water with a chemical adapted to render the water conductive,passing the mixture through an electrolytic cell, and causing the mixture to be thereafter retained in a larger tank or vat while precipitation of the earth takes place, and then decanting the clear water.

7. Ihe process of from impurities consisting. in mixing the separating fullers earth earth with water, rendering the Water conductive by the addition of a suitable chemical, causing the mixture to flow through an electrolytic cell, causing a current of electricity to pass through the mixture across its direction of flow, and thereafter conducting the mixture to a settling tank, and then subjecting the mixture to electrolytic action.

8. The process of separating fullers earth from impurities and precipitating such earth which consists in mixing the earth with water, rendering the Water conductive by the addition of a suitable chemical, causing the mixture to flow rapidly through an electrolytic cell, subjecting the flowing mixture to a current of electricity passing therethrough in a direction transverse to the flow, conducting the mixture to a settling tank wherein it flows slowly through said tank and there subjecting the mixture to electrolytilg action during its transit through such tan 9. The process of precipitating finely divided mineral matter from its suspension in a solution containing organic matter consisting in adding sultable chemicals to the said matter with water,.adding chemicals to the mixture, said chemicals being of a nature to render the mixture conducting and adapted to be decomposed by an electric current into substances having a bleaching effect, and passing an electric current through the solution so formed.

11. The process of enhancing the bleaching effect of fullers earth consisting in mixing the earth with water, adding suitable chemicals to the mixture so as to render the mixture conducting, said chemicals being adapted to be decomposed by electrolysis into substances having a bleaching effect, and electrolyzing the solution so formed.

In testimony whereof, I hereunto aflix my signature in the presence of two witnesses.

CHARLES C. RUPRECHT.

Witnesses:

. J. E. ANDERSON, D. C ANDERSON. 

